Polyimides, such as those described in Edwards, U.S. Pat. No. 3,179,614, can be used in a wide variety of commercial applications. The outstanding performance characteristics of these polymers under stress and at high temperatures have made them useful in the form of bushings, seals, electrical insulators, compressor vanes and impellers, pistons and piston rings, gears, thread guides, cams, brake linings, and clutch faces.
It is often desirable to incorporate various additives in such polyimide compositions before fabrication into their final form. Accordingly, graphite has been incorporated to improve the wear characteristics in bearing applications. Diamonds have been incorporated for abrasive applications. Fluoropolymers have been incorporated in the past for lubricity in forming and extrusion of shapes.
Despite the variety of polyimides and additives that have previously been available, a continuing problem for fabricated polyimide articles is their wear against aluminum. Specifically, even with the incorporation of graphite or other known lubricants, bearing surfaces in which polyimide and aluminum are brought into contact result in significant wear of both surfaces.